31. Next Permutation [M] improve

coderbean · coderbean · commit 402d29052ba4 · 2019-03-14T14:17:32.000+08:00
diff --git a/src/leetcode/_31_/Solution.java b/src/leetcode/_31_/Solution.java
@@ -14,9 +14,7 @@ private boolean isDone(int[] nums, int begin) {
         }
         if (end - begin == 2) {
             boolean result = nums[end - 1] > nums[begin];
-            int temp = nums[end - 1];
-            nums[end - 1] = nums[begin];
-            nums[begin] = temp;
+            swap(nums, begin, end);
             return result;
         }
         if (this.isDone(nums, begin + 1)) {
@@ -25,9 +23,7 @@ private boolean isDone(int[] nums, int begin) {
             int tmp = begin + 1;
             while (tmp < end) {
                 if (nums[begin] < nums[tmp]) {
-                    int temp = nums[begin];
-                    nums[begin] = nums[tmp];
-                    nums[tmp] = temp;
+                    swap(nums,begin,tmp);
                     return true;
                 }
                 tmp++;
@@ -36,4 +32,10 @@ private boolean isDone(int[] nums, int begin) {
             return false;  // [1,3,5,2,4]
         }
     }
+
+    private void swap(int[] nums, int begin, int end) {
+        int temp = nums[end - 1];
+        nums[end - 1] = nums[begin];
+        nums[begin] = temp;
+    }
 }

Original file line number	Diff line number	Diff line change
`@@ -14,9 +14,7 @@ private boolean isDone(int[] nums, int begin) {`
`14`	`14`	`}`
`15`	`15`	`if (end - begin == 2) {`
`16`	`16`	`boolean result = nums[end - 1] > nums[begin];`
`17`		`- int temp = nums[end - 1];`
`18`		`- nums[end - 1] = nums[begin];`
`19`		`- nums[begin] = temp;`
	`17`	`+ swap(nums, begin, end);`
`20`	`18`	`return result;`
`21`	`19`	`}`
`22`	`20`	`if (this.isDone(nums, begin + 1)) {`
`@@ -25,9 +23,7 @@ private boolean isDone(int[] nums, int begin) {`
`25`	`23`	`int tmp = begin + 1;`
`26`	`24`	`while (tmp < end) {`
`27`	`25`	`if (nums[begin] < nums[tmp]) {`
`28`		`- int temp = nums[begin];`
`29`		`- nums[begin] = nums[tmp];`
`30`		`- nums[tmp] = temp;`
	`26`	`+ swap(nums,begin,tmp);`
`31`	`27`	`return true;`
`32`	`28`	`}`
`33`	`29`	`tmp++;`
`@@ -36,4 +32,10 @@ private boolean isDone(int[] nums, int begin) {`
`36`	`32`	`return false; // [1,3,5,2,4]`
`37`	`33`	`}`
`38`	`34`	`}`
	`35`	`+`
	`36`	`+ private void swap(int[] nums, int begin, int end) {`
	`37`	`+ int temp = nums[end - 1];`
	`38`	`+ nums[end - 1] = nums[begin];`
	`39`	`+ nums[begin] = temp;`
	`40`	`+ }`
`39`	`41`	`}`